As far as I can tell, the BeorningAttributes is the object returned by calling GetClassAttributes() on a LocalPlayer that's a Beorning. It has two function calls:

GetWrath() - returns the current amount of Wrath (out of 100)
IsInBearForm() - returns a boolean indicating if you're in bear form or not

Also, there are two events:

WrathChanged - triggers on Wrath changing
FormChanged - triggers on changing to a bear or to a human

Not sure what else'll be in the documentation update (and I kinda hope they move Wrath out of the BeorningAttributes - can't access it in party members, so I can't make PartyFrame show the Wrath of Beorning party members. You're stuck with it displaying power.)

* Lua Plugins: Using LocalPlayer::GetWallet() at initialization time will no longer give you an empty wallet when loading the plugin via the Plugin Manager's "auto-load" options.
* Lua Plugins: When pressing the "Inventory Panel" hotkey, the inventory bags will no longer show up when disabled via a plugin.
* Lua Scripts: The returned table for Turbine.Shell.GetCommands is now property 1-based rather than 0-based.
* The Beorning class has been hooked up with Lua plugin support. See the updated Lua documentation for information on how to use the BeorningAttributes class.
* Lua - Added the "bridle" slot to the GetEquipment object and fixed a crash that would result on unloading plugins after calling GetEquipment.
* Lua - fixed the Listbox Sort method to correctly update the internal item array so that you can continue working with the listbox after sorting it.
* Lua - fixed a situation where SetBackground call could crash if passed in an unsupported image format